Roll src/third_party/angle/ af2b33be5..b3474d9d7 (2 commits)

https://chromium.googlesource.com/angle/angle.git/+log/af2b33be5a3a..b3474d9d77de

$ git log af2b33be5..b3474d9d7 --date=short --no-merges --format='%ad %ae %s'
2018-04-20 oetuaho Clean up ClipRectangle
2018-04-23 oetuaho Restrict BlitFramebuffer dimensions in WebGL mode

Created with:
  roll-dep src/third_party/angle
BUG=chromium:830046,chromium:830046


The AutoRoll server is located here: https://angle-chromium-roll.skia.org

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.


CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
TBR=geofflang@chromium.org

Change-Id: Ia3181cdc2541c174f2c8b7f5fd3001448ec2b470
Reviewed-on: https://chromium-review.googlesource.com/1024535Reviewed-by: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: angle-chromium-autoroll <angle-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#552874}

DEPS

@@ -102,7 +102,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling ANGLE
   # and whatever else without interference from each other.
-  'angle_revision': 'af2b33be5a3a4008bacdbcd857200e1a4b103534',
+  'angle_revision': 'b3474d9d77de3b3b204a5e559cf645dbb5b93981',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling build tools
   # and whatever else without interference from each other.